1. Field of the Invention
The present invention relates to a sliding panel for a vehicle roof, and more particularly to a vehicle sliding roof panel employing a member for horizontally and vertically positioning the panel.
2. Description of the Prior Art
In a conventional sliding roof panel for a vehicle, as shown in FIG. 1, the roof panel 2 is mounted so as to open and close an opening 1a in the roof 1 providing a so-called sun roof. The sliding panel is normally opened and closed by a driving apparatus mounted in a portion of the roof located at the front of the vehicle.
In such a type of sliding roof panel, a frame for the panel 2 includes a front bracket 3 and a rear bracket 4, the front bracket including a guide roller 3a. Rear bracket 4 includes guide slot 5 having a horizontal portion and an inclined portion angled upwardly from the rear end of the horizontal portion. A link 6 has a guide pin 7 affixed thereto and inserted into guide slot 5. In addition, a rear guide roller 8 is attached to link 6. A guide rail 9, which is disposed in roof 1 and extends under the opening 1a, allows guide rollers 3a, 8, to be inserted therein. Thereby, sliding roof panel 2 can slide rearward and forward along guide rail 9 by means of conventional drive cables (not shown).
FIG. 1 depicts conventional roof panel 2 in the closed position. The opening 1a is exposed when panel 2 is actuated so as to be open. When sliding roof panel 2 is being opened, by being drawn toward the rear of the vehicle, guide pin 7 of link 6 is moved toward the upper end of the inclined portion of guide slot 5 of bracket 4. Accordingly, the rear section of sliding roof 2 is forced to a lower position than depicted in FIG. 1 and is at a level approximately equivalent to the midsection of front guide roller 3a. The sliding roof therefore can be drawn under roof 1 by further horizontal rearward displacement of link 6.
In order to close sliding roof panel 2, link 6 is drawn forwardly, i.e., to the left in FIG. 1, until the front end of the panel contacts the front edge of the opening 1a. When the horizontal movement of panel 2 is stopped, link 6 continues forwardly forcing guide pin 7 from the inclined portion of guide slot 5 to the horizontal portion. Since the vertical disposition of guide pin 7 remains constant, the rear portion of sliding roof 2 is raised above the center of rear guide roller 3, closing the opening 1a.
In the prior art structure, opening the sun roof, as the guide pin 7 is translated from a horizontal to an inclined path, forcing the roof panel downwardly, an increased load is suddenly imposed on the drive cables increasing their fatigue.